Light-emitting display device and method of manufacturing the same

ABSTRACT

A light-emitting display device includes: a first substrate, a subpixel on the substrate, a contact area on the first substrate, a cover layer including first to third cover layer portions separated from each other, a first passivation layer, the first passivation layer exposing part of the third cover layer portion, a second passivation layer, a pixel electrode layer including a plurality of pixel electrode layer portions including: a first pixel electrode layer portion, and a second pixel electrode layer portion, an organic insulating layer, the organic insulating layer including: an opening exposing part of the first pixel electrode layer, and a contact hole exposing part of the second pixel electrode layer, an organic emissive layer, and a common electrode layer electrically connected to the second pixel electrode layer, wherein the opening includes a first undercut shape and a second undercut shape.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of and priority to Korean PatentApplication No. 10-2017-0166243, filed on Dec. 5, 2017, the entirety ofwhich is hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a light-emitting display device and amethod of manufacturing the same.

2. Discussion of the Related Art

The market for displays, which act as an intermediary between users andinformation, is growing with the development of information technology.Thus, display devices, such as light-emitting displays (LEDs), liquidcrystal displays (LCDs), and plasma display panels (PDPs) areincreasingly used.

Of the aforementioned displays, a light-emitting display includes adisplay panel including a plurality of subpixels, a drive part thatdrives the display panel, and a power supply part that supplies electricpower to the display panel. The drive part includes a scan driver thatsupplies scan signals (or gate signals) to the display panel and a datadriver that supplies data signals to the display panel.

In the light-emitting display, when scan signals, data signals, etc. aresupplied to subpixels arranged in a matrix, the light-emitting diodes ofselected subpixels emit light, thereby displaying an image. Thelight-emitting display may be classified as a “bottom-emission” typethat emits light toward a first substrate or a “top-emission” type thatemits light toward a second substrate. The light-emitting displays ofthe related art still require improvement for large-area applications.

SUMMARY

Accordingly, the present disclosure is directed to a light-emittingdisplay device and a method of manufacturing the same that substantiallyobviate one or more of the issues due to limitations and disadvantagesof the related art.

Additional features and aspects will be set forth in the descriptionthat follows, and in part will be apparent from the description, or maybe learned by practice of the inventive concepts provided herein. Otherfeatures and aspects of the inventive concepts may be realized andattained by the structure particularly pointed out in the writtendescription, or derivable therefrom, and the claims hereof as well asthe appended drawings.

To achieve these and other aspects of the inventive concepts as embodiedand broadly described, there is provided a light-emitting displaydevice, including: a first substrate, an interlayer insulating layer onthe first substrate, a subpixel on the substrate, the subpixelincluding: a light-emitting area, and a non-light-emitting area, acontact area on the first substrate, a metal layer on the interlayerinsulating layer on the first substrate, the metal layer including aplurality of metal layer portions, the plurality of metal layer portionsincluding: first and second metal layer portions disposed separately inthe light-emitting area and in the non-light-emitting area, and a thirdmetal layer portion disposed in the contact area, a cover layerincluding a plurality of cover layer portions including first to thirdcover layer portions disposed separately and respectively correspondingto the first to third metal layer portions, a first passivation layercovering the third cover layer portion in the contact area, the firstpassivation layer exposing part of the third cover layer portion, asecond passivation layer covering the first cover layer portion and thesecond cover layer portion, exposing part of the second cover layerportion, covering the first passivation layer, and exposing part of thethird cover layer portion, a pixel electrode layer including a pluralityof pixel electrode layer portions including: a first pixel electrodelayer portion on the second cover layer portion, and a second pixelelectrode layer portion on the third cover layer portion, an organicinsulating layer on the second passivation layer, the organic insulatinglayer including: an opening exposing part of the first pixel electrodelayer, and a contact hole exposing part of the second pixel electrodelayer, an organic emissive layer on the organic insulating layer and thefirst and second pixel electrode layers, and a common electrode layer onthe organic emissive layer, the common electrode layer beingelectrically connected to the second pixel electrode layer in thecontact area, wherein the opening includes a first undercut shapeincluding a recess of the second passivation layer into the bottom ofthe organic insulating layer partially exposing the bottom of theorganic insulating layer, and wherein the contact hole includes a secondundercut shape including a recess of the first passivation layer and thesecond passivation layer into the bottom of the organic insulating layerpartially exposing the bottom of the organic insulating layer.

In another aspect, there is provided a first substrate, a subpixel onthe substrate, a contact area on the first substrate, a cover layerincluding a plurality of cover layer portions including first to thirdcover layer portions, each of the first to third cover layer portionsbeing separated from each other, a first passivation layer covering thethird cover layer portion in the contact area, the first passivationlayer exposing part of the third cover layer portion, a secondpassivation layer covering the first cover layer portion and the secondcover layer portion, exposing part of the second cover layer portion,covering the first passivation layer, and exposing part of the thirdcover layer portion, a pixel electrode layer including a plurality ofpixel electrode layer portions including: a first pixel electrode layerportion on the second cover layer portion, and a second pixel electrodelayer portion on the third cover layer portion, an organic insulatinglayer on the second passivation layer, the organic insulating layerincluding: an opening exposing part of the first pixel electrode layer,and a contact hole exposing part of the second pixel electrode layer, anorganic emissive layer on the organic insulating layer and the first andsecond pixel electrode layers, and a common electrode layer on theorganic emissive layer, the common electrode layer being electricallyconnected to the second pixel electrode layer in the contact area,wherein the opening includes a first undercut shape including a recessof the second passivation layer into the bottom of the organicinsulating layer partially exposing the bottom of the organic insulatinglayer, wherein the contact hole includes a second undercut shapeincluding a recess of the first passivation layer and the secondpassivation layer into the bottom of the organic insulating layerpartially exposing the bottom of the organic insulating layer, andwherein a distance between the third cover layer portion and the organicinsulating layer is different from a distance between the first coverlayer portion and the organic insulating layer.

In another aspect, there is provided a method of manufacturing alight-emitting display device, the method including: providing a firstsubstrate, providing a subpixel on the substrate, the providing thesubpixel including: providing a light-emitting area, and providing anon-light-emitting area, providing a contact area on the firstsubstrate, providing a cover layer including providing a plurality ofcover layer portions including first to third cover layer portionsdisposed separate from each other, covering the third cover layerportion in the contact area with a first passivation layer, the firstpassivation layer exposing part of the third cover layer portion,providing a second passivation layer covering the first cover layerportion and the second cover layer portion, exposing part of the secondcover layer portion, covering the first passivation layer, and exposingpart of the third cover layer portion, providing a pixel electrode layerincluding providing a plurality of pixel electrode layer portionsincluding: providing a first pixel electrode layer portion on the secondcover layer portion, and providing a second pixel electrode layerportion on the third cover layer portion, providing an organicinsulating layer on the second passivation layer, the providing theorganic insulating layer including: providing an opening that exposespart of the first pixel electrode layer, and providing a contact holethat exposes part of the second pixel electrode layer, providing anorganic emissive layer on the organic insulating layer and the first andsecond pixel electrode layers, and providing a common electrode layer onthe organic emissive layer, the common electrode layer beingelectrically connected to the second pixel electrode layer, wherein theopening is provided with a first undercut shape formed by recessing thesecond passivation layer into the bottom of the organic insulating layerto partially expose the bottom of the organic insulating layer, whereinthe contact hole is provided with a second undercut shape formed byrecessing the first passivation layer and the second passivation layerinto the bottom of the organic insulating layer to partially expose thebottom of the organic insulating layer, and wherein the first and secondpixel electrode portions are self-aligned.

Other systems, methods, features and advantages will be, or will become,apparent to one with skill in the art upon examination of the followingfigures and detailed description. It is intended that all suchadditional systems, methods, features and advantages be included withinthis description, be within the scope of the present disclosure, and beprotected by the following claims. Nothing in this section should betaken as a limitation on those claims. Further aspects and advantagesare discussed below in conjunction with embodiments of the disclosure.It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure areexamples and explanatory, and are intended to provide furtherexplanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, that may be included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the description serve to explain various principles of thedisclosure.

FIG. 1 is a schematic block diagram of an organic light-emittingdisplay.

FIG. 2 is a schematic circuit diagram of a subpixel.

FIGS. 3A and 3B illustrates examples of a detailed circuit configurationof a portion of FIG. 2.

FIG. 4 illustrates an example of the plane of a display panel.

FIGS. 5A and 5B illustrate examples of a cross-section taken along theline 11-12 of FIG. 4.

FIG. 6 is a cross-sectional view of a portion of the display panelaccording to a test example embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of a portion of the display panelaccording to a first example embodiment of the present disclosure.

FIGS. 8 to 15 illustrate a manufacturing method of the display panelaccording to the first example embodiment of the present disclosure.

FIG. 16 is a cross-sectional view of a portion of the display panelaccording to a second example embodiment of the present disclosure.

FIGS. 17A to 19B illustrate examples of an array of auxiliary linesaccording to a third example embodiment of the present disclosure.

Throughout the drawings and the detailed description, unless otherwisedescribed, the same drawing reference numerals should be understood torefer to the same elements, features, and structures. The relative sizeand depiction of these elements may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which may be illustrated in the accompanyingdrawings. In the following description, when a detailed description ofwell-known functions or configurations related to this document isdetermined to unnecessarily cloud a gist of the inventive concept, thedetailed description thereof will be omitted. The progression ofprocessing steps and/or operations described is an example; however, thesequence of steps and/or operations is not limited to that set forthherein and may be changed as is known in the art, with the exception ofsteps and/or operations necessarily occurring in a particular order.Like reference numerals designate like elements throughout. Names of therespective elements used in the following explanations are selected onlyfor convenience of writing the specification and may be thus differentfrom those used in actual products.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

The term “at least one” should be understood as including any and allcombinations of one or more of the associated listed items. For example,the meaning of “at least one of a first item, a second item, and a thirditem” denotes the combination of all items proposed from two or more ofthe first item, the second item, and the third item as well as the firstitem, the second item, or the third item.

In the description of embodiments, when a structure is described asbeing positioned “on or above” or “under or below” another structure,this description should be construed as including a case in which thestructures contact each other as well as a case in which a thirdstructure is disposed therebetween. The size and thickness of eachelement shown in the drawings are given merely for the convenience ofdescription, and embodiments of the present disclosure are not limitedthereto.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. Embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. Embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in a co-dependent relationship.

Hereinafter, a display apparatus according to an embodiment of thepresent disclosure will be described in detail with reference to theaccompanying drawings. In adding reference numerals to elements of eachof the drawings, although the same elements are illustrated in otherdrawings, like reference numerals may refer to like elements.

A light-emitting display device to be described below may be implementedas a television, a video player, a personal computer (PC), a hometheater, a smartphone, a virtual reality (VR) device, an augmentedreality (AR) device, etc. The light-emitting display device isapplicable to an inorganic light-emitting display device based oninorganic light-emitting diodes, as well as an organic light-emittingdisplay device based on organic light-emitting diodes (light-emittingdisplay elements). The following description will be given with respectto an organic light-emitting display device by way of example.

FIG. 1 is a schematic block diagram of an organic light-emittingdisplay. FIG. 2 is a schematic circuit diagram of a subpixel. FIGS. 3Aand 3B illustrates examples of a detailed circuit configuration of aportion of FIG. 2. FIG. 4 illustrates an example of the plane of adisplay panel. FIGS. 5A and 5B illustrate examples of a cross-sectiontaken along the line 11-12 of FIG. 4.

As shown in the FIG. 1 example, the organic light-emitting display mayinclude a timing controller 180, a data driver 130, a scan driver 140, adisplay panel 110, and a power supply part 160. The timing controller180 may receive drive signals, including a data enable signal, avertical synchronization signal, a horizontal synchronization signal,and a clock signal, along with data signals DATA, from an imageprocessor (not shown). Based on the drive signals, the timing controller180 may output a gate timing control signal GDC for controlling theoperation timing of the scan driver 140 and a data timing control signalDDC for controlling the operation timing of the data driver 130. Thetiming controller 180 may be provided in the form of an integratedcircuit (IC).

The data driver 130 may sample and latch a data signal DATA suppliedfrom the timing controller 180 in response to a data timing controlsignal DDC supplied from the timing controller 180, and may convert adigital data signal to an analog data signal (or data voltage) as agamma reference voltage and may output the converted digital datasignal. The data driver 130 may output data signals DATA through datalines DL1 to DLn. The data driver 130 may be provided in the form of anIC.

The scan driver 140 may output scan signals in response to a gate timingcontrol signal GDC supplied from the timing controller 180. The scandriver 140 may output scan signals through scan lines (or gate lines)GL1 to GLm. The scan driver 140 may be provided in the form of an IC ormay be formed on the display panel 110 using gate-in-panel technology inwhich transistors are formed using a thin-film process.

The power supply part 160 may output a high-level voltage and alow-level voltage. The high-level voltage and low-level voltageoutputted from the power supply part 160 may be supplied to the displaypanel 110. The high-level voltage may be supplied to the display panel110 via a first power line EVDD, and the low-level voltage may besupplied to the display panel 110 via a second power line EVSS. Thepower supply part 160 may be provided in the form of an IC.

The display panel 110 may display an image in response to data signalsDATA supplied from the data driver 130, scan signals supplied from thescan driver 140, and electric power supplied from the power supply part160. The display panel 110 may include subpixels SP that work to displayan image and emit light.

The subpixels SP may include red subpixels, green subpixels, and bluesubpixels, or may include white subpixels, red subpixels, greensubpixels, and blue subpixels. Embodiments are not limited to theseexamples. The subpixels SP may have one or more different light-emissionareas depending on the light-emission characteristics.

As shown in the FIG. 2 example, a single subpixel may be positioned atthe intersection of a data line DL1 and a scan line GL1, and may includea programming part SC for setting the gate-source voltage of a drivingtransistor DR and an organic light-emitting diode OLED. The organiclight-emitting diode OLED may include an anode ANO, a cathode CAT, andan organic emissive layer sandwiched between the anode ANO and thecathode CAT. The anode ANO may be connected to the driving transistorDR.

The programming part SC may include a transistor part (e.g., atransistor array) including at least one switching transistor and atleast one capacitor. The transistor part may be implemented based on acomplementary metal-oxide-semiconductor (CMOS) semiconductor, a p-typemetal-oxide-semiconductor (PMOS) semiconductor, or an n-typemetal-oxide-semiconductor (NMOS) semiconductor. The transistors in thetransistor part may be implemented as p-type or n-type. Moreover,semiconductor layers of the transistors included in the transistor partof the subpixel may contain amorphous silicon, polysilicon, or oxide.Embodiments are not limited to these examples.

The switching transistor may turn on in response to a scan signal fromthe scan line GL1 to apply a data voltage from the data line DL1 to oneelectrode of the capacitor. The driving transistor DT may adjust theamount of light emitted from the organic light-emitting diode OLED bycontrolling the amount of current depending on the amount of voltagestored in the capacitor. The amount of light emitted from the organiclight-emitting diode OLED is proportional to the amount of currentsupplied from the driving transistor DT. Also, the subpixel may beconnected to a first power supply line EVDD and a second power supplyline EVSS to receive high-level voltage and low-level voltage.

As shown in the FIG. 3A example, the subpixel may include an internalcompensation circuit CC, as well as the aforementioned switchingtransistor SW, driving transistor DR, capacitor Cst, and organiclight-emitting diode OLED. The internal compensation circuit CC mayinclude one or more transistors connected to a compensation signal lineINIT. The internal compensation circuit CC may set the gate-sourcevoltage of the driving transistor DR to a voltage that reflectsvariation in threshold voltage to reduce or cancel out any brightnessvariation caused by the threshold voltage of the driving transistor DRwhen the organic light-emitting diode OLED emits light. For example, thescan line GL1 may include at least two scan lines GL1 a and GL1 b forcontrolling the switching transistor SW and the transistors in theinternal compensation circuit CC.

As shown in the FIG. 3B example, the subpixel may include a switchingtransistor SW1, a driving transistor DR, a sensing transistor SW2, acapacitor Cst, and an organic light-emitting diode OLED. The sensingtransistor SW2 is a transistor that may be included in the internalcompensation circuit CC, and may perform a sensing operation forcompensating for the subpixel.

The switching transistor SW1 may supply a data voltage, supplied throughthe data line DL1 to a first node N1, in response to a scan signalsupplied through the first scan line GL1 a. The sensing transistor SW2may reset or sense a second node N2, situated between the drivingtransistor DR and the organic light-emitting diode OLED, in response toa sensing signal supplied through the second scan line GL1 b.

Meanwhile, the above circuit configuration of the subpixel depicted inthe examples of FIGS. 3A and 3B is illustrated for ease ofcomprehension. That is, the circuit configuration of the subpixelaccording to an embodiment of the present disclosure is not limited tothe above example, but may vary, including, e.g., 2T (transistor) 1C(capacitor), 3T2C, 4T2C, 5T1C, 6T2C, and 7T2C configurations.

As shown in the FIG. 4 example, the display panel 110 may include afirst substrate 110 a, a second substrate 110 b, a display area AA, anda pad part PAD. The display area AA may include subpixels SP that mayemit light. While the subpixels SP in the display area AA may be sealedbecause of their sensitivity to moisture or oxygen, the pad part PAD maybe exposed because it may include pads for facilitating an electricalconnection with an external substrate.

The display area AA may occupy most of the surface of the firstsubstrate 110 a, and the pad part PAD may be on one outer edge of thefirst substrate 110 a. The display panel 110 may be rectangular, butembodiments are not limited thereto. For example, the display panel 110may have various shapes, such as a pentagon, hexagon, polygon, circle,or oval. An oval shape may include an elliptical shape, an egg-shape, arectangular shape with rounded corners, or other non-circular curvedshape having a width different from its height.

As shown in the examples of FIG. 4 and FIG. 5A, the display area AA maybe sealed with a sealing member 170 between the first substrate 110 aand second substrate 110 b. As shown in the examples of FIG. 4 and FIG.5B, the display area AA may be sealed with the first substrate 110 a andsecond substrate 110 b alone.

The display panel 110 may be provided in various shapes, including flat,flexible or stretchable, or curved. Moreover, the display panel 110 maybe implemented as a bottom-emission type that may emit light toward thefirst substrate 110 a, a top-emission type that may emit light towardthe second substrate 110 b, or a dual-emission type that may emit lighttoward both of the substrates 110 a and 110 b. Therefore, the sealingstructure of the display panel 110 may be selected to conform to adesired shape, and is therefore not limited to what is depicted in FIGS.4 and 5. Below, the top-emission type will be described as an example ofthe large-area display panel 110.

Test Example

FIG. 6 is a cross-sectional view of a portion of the display panelaccording to a test example embodiment of the present disclosure.

As shown in the example of FIG. 6, the display panel according to thetest example may include a first substrate 110 a, a transistor TFT, anorganic light-emitting diode OLED, and a second substrate 110 b. Thetransistor TFT and the organic light-emitting diode OLED may be includedin a light-emitting area SPA of a subpixel.

A non-light-emitting area NA may be adjacent to the light-emitting areaSPA of the subpixel. A contact area CNA may be adjacent to thenon-light-emitting area NA. In areas other than the light-emitting areaSPA of the subpixel, light emission may not actually occur. Thus, thecontact area CNA may also be included in the non-light-emitting area NA.However, it should be noted that the contact area CNA may be provided toconnect a common electrode layer 123 of the organic light-emitting diodeOLED to an auxiliary line AUX, and may therefore be defined as aseparate area because of its functional differences from thenon-light-emitting area NA. The components included in the display panelaccording to the test example will be discussed in further detail withregard to in the example embodiments below, so detailed descriptionsthereof will be omitted.

In the test example, the auxiliary line AUX may improve brightnessuniformity on a large-area, top-emission display panel. The auxiliaryline AUX may include multiple layers to help reduce the resistance ofthe common electrode layer 123. The auxiliary line AUX may include afirst auxiliary electrode layer portion 116 c, which may be one of metallayer portions 116 a, 116 b, and 116 c, a second auxiliary electrodelayer portion 117 c, which may be one of cover layer portions 117 a, 117b, and 117 c, and a third auxiliary electrode layer portion 120 b, whichmay be one of pixel electrode layers 120, 120 a, and 120 b. The thirdauxiliary electrode layer portion 120 b at the uppermost part of theauxiliary line AUX may be electrically connected to the common electrodelayer 123.

In the test example, an organic emissive layer 122 is situated betweenthe common electrode layer 123 and the third auxiliary electrode layerportion 120 b at the uppermost part of the auxiliary line AUX, due tothe characteristics of the manufacturing process. Thus, the structure ofthe test example uses laser irradiation to bring the common electrodelayer 123 and the third auxiliary electrode layer portion 120 b at theuppermost part of the auxiliary line AUX into electrical contact witheach other. In the example embodiment of the present disclosuredescribed below, the auxiliary line AUX provided on the large-area,top-emission display panel to help reduce the resistance of the commonelectrode layer 123 may allow for contact between electrodes without anylaser irradiation process.

First Example Embodiment

FIG. 7 is a cross-sectional view of a portion of the display panelaccording to a first example embodiment of the present disclosure.

As shown in the FIG. 7 example, the display panel according to the firstexample embodiment may include a first substrate 110 a, a transistorTFT, an organic light-emitting diode OLED, and a second substrate 110 b.The transistor TFT and the organic light-emitting diode OLED may beincluded in a light-emitting area SPA of a subpixel.

A non-light-emitting area NA may be adjacent to the light-emitting areaSPA of the subpixel. A contact area CNA may be adjacent to thenon-light-emitting area NA. In areas other than the light-emitting areaSPA of the subpixel, light emission may not actually occur. Thus, thecontact area CNA may also be included in the non-light-emitting area NA.However, it should be noted that the contact area CNA may be provided toconnect a common electrode layer 123 of the organic light-emitting diodeOLED to an auxiliary line AUX, and may therefore be defined as aseparate area because of its functional differences from thenon-light-emitting area NA.

The structures formed between the two substrates 110 a and 110 b will bedescribed below. However, it should be noted that the cross-sectionalstructure seen in the light-emitting area SPA of the subpixel maycorrespond to a portion of a single subpixel. In the followingdescription, as long as these structures are formed on the front side ofthe substrates, the structures between the two substrates 110 a and 110b may be located in the light-emitting area SPA of the subpixel or inthe contact area CNA.

A buffer layer 111 may be on the first substrate 110 a. A semiconductorlayer 112 may be on the buffer layer 111. The semiconductor layer 112may be in the display area AA, and may have a source region, a channelregion, and a drain region. A gate insulating layer 113 may be on thesemiconductor layer 112. The gate insulating layer 113 may cover thechannel region of the semiconductor layer 112 in the display area AA.

A gate metal layer 114 may be on the gate insulating layer 113. The gatemetal layer 114 may correspond to the size of the gate insulating layer113. The gate metal layer 114 may be a gate electrode of the transistorTFT. In addition, the gate metal layer 114 may form a scan line or thelike. An interlayer insulating layer 115 may be on the gate metal layer114. The interlayer insulating layer 115 may expose the source and drainregions of the semiconductor layer 112.

Metal layer portions 116 a, 116 b, and 116 c may be on the interlayerinsulating layer 115. The metal layer portions 116 a, 116 b, and 116 cmay be on the same level or layer. The metal layer portions 116 a, 116b, and 116 c may be divided into metal layer portions 116 a and 116 blocated in the light-emitting area SPA of the subpixel, and a metallayer portion 116 c located in the contact area CNA. The metal layerportions 116 a and 116 b in the light-emitting area SPA of the subpixelmay be separated to be connected to the source and drain regions of thesemiconductor layer 112. The first and second metal layer portions 116 aand 116 b may be source and drain electrodes of the transistor TFT. Thethird metal layer portion 116 c located in the contact area CNA may bedefined as the first auxiliary electrode layer portion 116 c of theauxiliary line AUX. The metal layer portions 116 a, 116 b, and 116 c mayform a data line and the source and drain electrodes of the transistorTFT, and may be defined as data metal layers.

Cover layer portions 117 a, 117 b, and 117 c may be on the metal layerportions 116 a, 116 b, and 116 c. The cover layer portions 117 a, 117 b,and 117 c may be on the same level or layer. The cover layer portions117 a, 117 b, and 117 c may be divided into cover layer portions 117 aand 117 b located in the light-emitting area SPA of the subpixel, and acover layer portion 117 c located in the contact area CNA. The first tothird cover layer portions 117 a, 117 b, and 117 c may be patterned tocover the metal layer portions 116 a, 116 b, and 116 c, respectively.The third cover layer portion 117 c may be defined as the secondauxiliary electrode layer portion 117 c of the auxiliary line AUX.

In the contact area CNA, a first passivation layer 118 may expose thethird cover layer portion 117 c (or part of the third metal layerportion 117 c if the third cover layer is not present). In thenon-light-emitting area NA, aside from the light-emitting area SPA ofthe subpixel, a second passivation layer 119 may expose the second coverlayer portion 117 b (or part of the second metal layer portion 117 b ifthe second cover layer is not present). The first passivation layer 118and the second passivation layer 119 may protect the underlyingstructure layer including the transistor TFT. In the contact area CNA,the first passivation layer 118 and the second passivation layer 119 maybe deposited on top of each other to form a thick passivation layer,whereas, in the non-light-emitting area NA, only the first passivationlayer 118 may be deposited to thereby form a relatively thin passivationlayer. The benefits of varying the thickness of the passivation layerfor each area will be discussed in detail below.

An organic insulating layer 121 may be on the second passivation layer119 in the non-light-emitting area NA and contact area CNA. The organicinsulating layer 121 may have an opening OPN defining the light-emittingarea SPA of the subpixel and a contact hole CNH defining the contactarea CNA. The pixel electrode layer portions 120 a and 120 b may bepartially exposed through the opening OPN and contact hole CNH formed inthe organic insulating layer 121, respectively. The organic insulatinglayer 121 may have an opening OPN defining the light-emitting area SPAof the subpixel. The opening OPN may have a first undercut shape UC1,which may be formed by recessing the second passivation layer 119 intothe bottom of the organic insulating layer 121 to partially expose thebottom of the organic insulating layer 121. Due to the first undercutshape UC1, the top of the second passivation layer 119 may be narrowerin width than the bottom of the organic insulating layer 121. Althoughthe top of the second passivation layer 119 may contact the bottom ofthe organic insulating layer 121, part of the bottom of the organicinsulating layer 121 may be exposed without contacting the top of thesecond passivation layer 119.

The organic insulating layer 121 may have a contact hole CNH definingthe contact area CNA. The contact hole CNH may have a second undercutshape UC2, which may be formed by recessing the first passivation layer118 and the second passivation layer 119 into the bottom of the organicinsulating layer 121 to partially expose the bottom of the organicinsulating layer 121. Due to the second undercut shape UC2, the top ofthe first and second passivation layers 118 and 119 may be narrower inwidth than the bottom of the organic insulating layer 121. The width ofthe second passivation layer 119 may be greater than the width of thefirst passivation layer 118. Although the top of the second passivationlayer 119 may contact the bottom of the organic insulating layer 121,part of the bottom of the organic insulating layer 121 may be exposedwithout contacting the top of the second passivation layer 119.

The first undercut shape UC1 and the second undercut shape UC2 may havea similar shape. However, the second passivation layer 119 may existalone in an area around the opening OPN formed by the first undercutshape UC1, and both the first passivation layer 118 and the secondpassivation layer 119 may exist in an area around the contact area CNAformed by the second undercut shape UC2. The height H of the underlyingspace created by the first undercut shape UC1 and the height (H+α) ofthe underlying space created by the second undercut shape UC2 mayrepresented by the relationship UC1<UC2.

The pixel electrode layer portions 120 a and 120 b may be on the secondcover layer portion 117 b and third cover layer portion 117 c exposedthrough the organic emission layer 121. The first pixel electrode layerportion 120 a on the second cover layer portion 117 b in thelight-emitting area SPA of the subpixel may be defined as the anode ofthe organic light-emitting diode OLED. The second pixel electrode layerportion 120 b on the third cover layer portion 117 c in the contact areaCNA may be defined as a third auxiliary electrode layer portion 120 b ofthe auxiliary line AUX. The first pixel electrode layer portion 120 amay penetrate all the way into the underlying space created by the firstundercut shape UC1, and may cover the sidewall of the second passivationlayer 119. The second pixel electrode layer portion 120 b may penetrateall the way into the underlying space created by the second undercutshape UC2, and may cover the sidewall of the first passivation layer 118(and may also cover part of the second passivation layer 119).

The organic emissive layer 122 may be on the first pixel electrode layerportion 120 a, second pixel electrode 120 b, and organic insulatinglayer 121. The organic emissive layer 122 may include an organicemissive layer portion 122 a and an organic emissive layer portion 122b. The organic emissive layer 122 may include a material that may emitred, green, or blue light, or a material that may emit white light if acolor filter is present. Embodiments are not limited to these examples.The organic emissive layer portion 122 a on the first pixel electrodelayer portion 120 a may be formed along with the organic emissive layer122 on the organic insulating layer 121, but may be separated from itdue to the first undercut shape UC1. Likewise, the organic emissivelayer portion 122 b on the second pixel electrode layer portion 120 bmay be formed along with the organic emissive layer 122 on the organicemissive layer 121, but may be separated from it due to the secondundercut shape UC2. The organic emissive layer portion 122 a on thefirst pixel electrode layer portion 120 a may exist only in the openingOPN due to the first undercut shape UC1, it may occupy less area thanthe underlying first pixel electrode layer portion 120 a. The organicemissive layer portion 122 b on the second pixel electrode layer portion120 b may exist only in the contact hole CNH due to the second undercutshape UC2, it may occupy less area than the underlying second pixelelectrode layer portion 120 b. The organic emissive layer portion 122 bexisting in the contact hole CNH may not emit light. That is, no lightmay be emitted in the contact area CNA.

Due to the first undercut shape UC1, the organic emissive layer 122 onthe organic insulating layer 121 and the organic emissive layer portion122 a on the first pixel electrode layer portion 120 a may be separatedfrom each other. Also, the organic insulating layer 121 may have nopixel electrode layer portions 120 a and 120 b left on it, and this mayavoid or prevent a short circuit that may occur when the pixel electrodelayer portions 120 a and 120 b and the common electrode layer 123 comeinto contact with each other, even if the organic emissive layer portion122 a is not thin. The organic emissive layer portion 122 a on the firstpixel electrode layer portion 120 a may emit light, whereas the organicemissive layer portion 122 b on the second pixel electrode layer portion120 b may not emit light. As a result, the first example embodiment mayhave an advantage in reducing or preventing lateral current leakage,which may occur between neighboring subpixels.

The common electrode layer 123 may be on the organic emissive layer 122.The common electrode layer 123 may be defined as the cathode of theorganic light-emitting diode OLED. The common electrode layer 123 may beformed to fully cover the organic emissive layer 122 exposed in thedisplay area of the display panel, e.g., to cover all subpixels. Assuch, the common electrode layer 123 may extend seamlessly in thenon-light-emitting area NA and the contact area CNA, as well as acrossthe opening OPN defining the light-emitting area SPA of the subpixel.

Notably, in the common electrode layer 123, the underlying space createdby the second undercut shape UC2 may be taller than the underlying spacecreated by the first second shape UC1, due to the thickness of the firstpassivation layer 118 and second passivation layer 119 that lie underthe second undercut shape UC2. Therefore, the common electrode layer 123in the contact area CNA may cover the second pixel electrode layerportion 120 b exposed through the contact hole CNH and the organicemissive layer portion 122 b on the second pixel electrode layer portion120 b, as well as the sidewalls of the first passivation layer 118 andsecond passivation layer 119. As a result, the common electrode layer123 in the contact area CNA may be electrically connected to the secondpixel electrode layer portion 120 b at the uppermost part of theauxiliary line AUX, without an additional process, such as laserirradiation.

Thus, in the first example embodiment of the present disclosure, theorganic emissive layer 122 can be short-circuited simply by increasingthe thickness of the passivation layers 118 and 119 in the contact areaCNA, and at the same time the auxiliary line AUX and the commonelectrode layer 123 may be brought into contact with each other. Due tothis, when the common electrode layer 123 is formed, it may come intoelectrical contact with the second pixel electrode layer portion 120 bat the uppermost part of the auxiliary line AUX. Therefore, the firstexample embodiment of the present disclosure illustrated in the FIG. 7example can simplify the process as compared to the test exampleillustrated in the FIG. 6 example. According to the first exampleembodiment of the present disclosure, the common electrode layer 123 andthe second pixel electrode layer portion 120 b at the uppermost part ofthe auxiliary line AUX may come into contact with each other on thesidewall of the second passivation layer 119 exposed in the contact areaCNA. According to the first example embodiment of the presentdisclosure, the common electrode layer 123 may cover all the layersexposed in the contact area CNA.

Hereinafter, a manufacturing method of the display panel according tothe first example embodiment of the present disclosure will be describedbelow.

FIGS. 8 to 15 illustrate a manufacturing method of the display panelaccording to the first example embodiment of the present disclosure.

As shown in the FIG. 8 example, a buffer layer 111 may be formed on thefirst substrate 110 a. The buffer layer 111 may be composed of a singlelayer of silicon nitride (SiN_(x)) or silicon oxide (SiO_(x)), or may bemultiple layers of silicon nitride (SiN_(x)) and silicon oxide(SiO_(x)). The first substrate 110 a may include, e.g., a silicon-basedmaterial, although embodiments are not limited thereto.

A semiconductor layer 112 may be formed on the buffer layer 111. Thesemiconductor layer 112 may be located in the display area AA, and mayhave a source region, a channel region, and a drain region. Thesemiconductor layer 112 may be made of, e.g., an organic semiconductormaterial, an oxide semiconductor material, or a silicon semiconductormaterial.

A gate insulating layer 113 may be formed on the semiconductor layer112. The gate insulating layer 113 may cover the channel region of thesemiconductor layer 112 existing in the display area AA. The gateinsulating layer 113 may be composed of a single layer of siliconnitride (SiN_(x)) or silicon oxide (SiO_(x)), or may be multiple layersof silicon nitride (SiN_(x)) and silicon oxide (SiO_(x)).

A gate metal layer 114 may be formed on the gate insulating layer 113.The gate metal layer 114 may correspond to the size of the gateinsulating layer 113. The gate metal layer 114 may be a gate electrodeof the transistor TFT. In addition, the gate metal layer 114 may form ascan line or the like. The gate insulating layer 113 may include one ormore of: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au),titanium (Ti), nickel (Ni), and copper (Cu), or an alloy thereof, andmay be composed of a single layer or multiple layers. Embodiments arenot limited to these examples.

An interlayer insulating layer 115 may be formed on the gate metal layer114. The interlayer insulating layer 115 may be composed of a singlelayer of silicon nitride (SiN_(x)) or silicon oxide (SiO_(x)), or may bemultiple layers of silicon nitride (SiN_(x)) and silicon oxide(SiO_(x)). The interlayer insulating layer 115 may expose the source anddrain regions of the semiconductor layer 112.

The metal layer portions 116 a, 116 b, and 116 c may be formed on theinterlayer insulating layer 115. The metal layer portions 116 a, 116 b,and 116 c may include first and second metal layer portions 116 a and116 b connected separately to the source and drain regions of thesemiconductor layer 112 in the light-emitting area SPA of the subpixel,and a third metal layer portion 116 c separately located in the contactarea CNA. The first and second metal layer portions 116 a and 116 b maybe the source and drain regions of the transistor TFT, and the thirdmetal layer portion 116 c may be the first auxiliary electrode layerportion 116 c of the auxiliary line AUX. The metal layer portions 116 a,116 b, and 116 c may include one or more of: molybdenum (Mo), aluminum(Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and copper(Cu), or an alloy thereof, and may be composed of a single layer ormultiple layers. Embodiments are not limited to these examples.

The cover layer portions 117 a, 117 b, and 117 c may be formed on themetal layer portions 116 a, 116 b, and 116 c. The cover layer portions117 a, 117 b, and 117 c may be patterned, corresponding to the positionsof the metal layer portions 116 a, 116 b, and 116 c, to cover andprotect the metal layer portions 116 a, 116 b, and 116 c separated forthe light-emitting area SPA of the subpixel and the contact area CNA.Unlike the first and third cover layer portions 117 a and 117 c, thesecond cover layer portion 117 b may be patterned to also cover thechannel region. The third cover layer portion 117 c may be the secondauxiliary electrode layer portion 117 c of the auxiliary line. The coverlayer portions 117 a, 117 b, and 117 c may include oxides such as indiumtin oxide (ITO) and indium zinc oxide (IZO). The cover layer portions117 a, 117 b, and 117 c may be omitted due to the characteristics of theprocess. A first passivation layer 118 may be formed on the interlayerinsulating layer 115 and the cover layer portions 117 a, 117 b, and 117c. The first passivation layer may be is patterned so that part of itmay be located in the contact area CNA and the non-light-emitting areaNA. The first passivation layer 118 may expose the third cover layerportion 117 c located in the contact area CNA. The first passivationlayer 118 may be composed of a single layer of silicon nitride (SiN) orsilicon oxide (SiO_(x)), or may be multiple layers of silicon nitride(SiN) and silicon oxide (SiO_(x)).

As shown in the FIG. 9 example, a second passivation layer 119 may beformed on the interlayer insulating layer 115, the cover layer portions117 a, 117 b, and 117 c, and the first passivation layer 118. The secondpassivation layer 119 may exist alone in the non-light-emitting area NAadjacent to the light-emitting area SPA of the subpixel, and both thefirst passivation layer 118 and the second passivation layer 119 may beadjacent to the contact area CNA. As a result, the height H of thesecond passivation layer 119 adjacent to the light-emitting area SPA ofthe subpixel may be greater than the height (H+a) of the first andsecond passivation layers 118 and 119 adjacent to the contact area CNA.The second passivation layer 119 may include a material either the sameas or different from that of the first passivation layer 118. Thethickness of the second passivation layer 119 may be different than thethickness of the first passivation layer 118. The thickness (e.g.,greater than or equal to 1,000 Å) may be greater than the thickness(e.g., less than or equal to 1,000 Å) of the second passivation layer119. The thicker the first passivation layer 118 is than the secondpassivation layer 119, the better. The related benefits will bediscussed below.

As shown in the FIG. 10 example, an organic insulating layer 121 may beformed on the second passivation layer 119. The organic insulating layer121 may be made of an organic material, such as a negative overcoatlayer, polyimide, benzocyclobutene series resin, acrylate, and/orphotoacrylate, although embodiments are not limited to these examples.The organic insulating layer 121 may be patterned to form an opening OPNin the light-emitting area SPA of the subpixel and a contact hole CNH inthe contact area CNA.

As shown in the FIG. 11 example, the first passivation layer 118 andsecond passivation layer 119 exposed out of the organic insulating layer121 may be etched by using the organic insulating layer 121 as a mask.The first passivation layer 118 and the second passivation layer 119 maybe etched, e.g., by wet etching. A first undercut shape UC1 may beformed in the opening OPN defining the light-emitting area SPA of thesubpixel so that the underlying second passivation layer 119 may berecessed into the organic insulating layer 121. A second undercut shapeUC2 may be formed in the contact hole CNH defining the contact area CNAso that the underlying first and second passivation layers 118 and 119may be recessed into the organic insulating layer 121.

As shown in the FIG. 12 example, the pixel electrode layer portions 120a, 120 b, and 120 c may be formed by using the organic insulating layer121 as a mask. The pixel electrode layer portions 120 a, 120 b, and 120c may be separated into different positions by the organic insulatinglayer 121. The pixel electrode layer portions 120 a, 120 b, and 120 cmay be automatically separated by the organic insulating layer 121,which can be referred to as “self-alignment.” The first pixel electrodelayer portion 120 a on the second cover layer portion 117 b in thelight-emitting area SPA of the subpixel may be defined as the anode ofthe organic light-emitting diode OLED. The second pixel electrode layerportion 120 b on the third cover layer portion 117 c in the contact areaCNA may be defined as the third auxiliary electrode layer portion 120 bof the auxiliary line AUX.

As shown in the examples of FIGS. 13 and 14, photoresist PR may beformed by using the organic insulating layer 121 as a mask. Thephotoresist PR may be formed to remove the third pixel electrode layerportion 120 c left on the organic insulating layer 121. It may bepreferable that the photoresist PR be formed almost as high as thebottom of the organic insulating layer 121. Accordingly, the photoresistPR may be ashed and then removed, and at the same time, the third pixelelectrode layer portion 120 c left on the organic insulating layer 121may be removed.

As shown in the FIG. 15 example, the organic emissive layer 122,including organic emissive layer portions 122 a and 122 b may be formedby using the organic insulating layer 121 as a mask. The organicemissive layer 122 may be include a material that may emit red, green,or blue light, or a material that may emit white light if a color filteris present. Embodiments are not limited to these examples. The organicemissive layer portion 122 a on the first pixel electrode layer portion120 a may be formed along with the organic emissive layer 122 on theorganic insulating layer 121, but may be separated from it due to thefirst undercut shape UC1. Likewise, the organic emissive layer portion122 b on the second pixel electrode layer portion 120 b may be formedalong with the organic emissive layer 122 on the organic emissive layer121, but may be separated from it due to the second undercut shape UC2.

The organic emissive layer portion 122 a on the first pixel electrodelayer portion 120 a may exist only in the opening OPN due to the firstundercut shape UC1, and may occupy less area than the underlying firstpixel electrode layer portion 120 a. The organic emissive layer portion122 b on the second pixel electrode layer portion 120 b may exist onlyin the contact hole CNH due to the second undercut shape UC2, and mayoccupy less area than the underlying second pixel electrode layerportion 120 b. The organic emissive layer portion 122 a on the firstpixel electrode layer portion 120 a may emit light, whereas the organicemissive layer portion 122 b on the second pixel electrode layer portion120 b may not emit light. As a result, the first example embodiment mayhave an advantage in reducing or preventing lateral current leakage,which may occur between neighboring subpixels. Due to the first undercutshape UC1, the organic emissive layer 122 on the organic insulatinglayer 121 and the organic emissive layer portion 122 a on the firstpixel electrode layer portion 120 a may be separated from each other.Also, the organic insulating layer 121 may have no pixel electrode layerportions 120 a and 120 b left on it, and this may avoid or prevent ashort-circuit that may occur when the pixel electrode layer portions 120a and 120 b and the common electrode layer 123 come into contact witheach other, even if the organic emissive layer portion 122 a is notthin.

The common electrode layer 123 may be on the organic emissive layer 122.The common electrode layer 123 may be defined as the cathode of theorganic light-emitting diode OLED. The common electrode layer 123 mayfully cover the organic emissive layer 122 exposed in the display areaof the display panel, e.g., to cover all subpixels. As such, the commonelectrode layer 123 may extend seamlessly in the non-light-emitting areaNA and the contact area CNA, as well as across the opening OPN definingthe light-emitting area SPA of the subpixel.

Notably, in the common electrode layer 123, the underlying space createdby the second undercut shape UC2 may be taller than the underlying spacecreated by the first second shape UC1, due to the thickness of the firstpassivation layer 118 and second passivation layer 119 that lie underthe second undercut shape UC2. Therefore, the common electrode layer 123in the contact area CNA may cover the second pixel electrode layerportion 120 b exposed through the contact hole CNH and the organicemissive layer portion 122 b on the second pixel electrode layer portion120 b, as well as the sidewalls of the first passivation layer 118 andsecond passivation layer 119. As a result, the common electrode layer123 in the contact area CNA may be electrically connected to the secondpixel electrode layer portion 120 b at the uppermost part of theauxiliary line AUX, without an additional process, such as laserirradiation. To facilitate this function, it may be preferable that thefirst passivation layer 118 exists only in the contact area CNA. This isbecause, the thicker the first passivation layer 118, the wider thedeposition area and contact area of the electrode layers that maypenetrate into its sidewall.

Thus, in the first example embodiment of the present disclosure, theorganic emissive layer 122 can be short-circuited simply by increasingthe thickness of the passivation layers 118 and 119 in the contact areaCNA, and at the same time the auxiliary line AUX and the commonelectrode layer 123 may be brought into contact with each other. Due tothis, when the common electrode layer 123 is formed, it may come intoelectrical contact with the second pixel electrode layer portion 120 bat the uppermost part of the auxiliary line AUX. Therefore, the firstexample embodiment of the present disclosure can simplify the process ascompared to the test example. The first example embodiment of thepresent disclosure is useful for, but is not limited to, a structure inwhich an auxiliary line is added and brought into contact with a commonelectrode layer to overcome the problem of resistance increase caused bythe materials of electrode layers used especially in top-emissiondisplays, and also may be used to reduce the resistance ofbottom-emission displays.

Second Example Embodiment

FIG. 16 is a cross-sectional view of a portion of the display panelaccording to a second example embodiment of the present disclosure.

As shown in the FIG. 16 example, the display panel according to thesecond example embodiment may include a first substrate 110 a, atransistor TFT, an organic light-emitting diode OLED, a black matrixlayer BM, a color filter layer CF, and a second substrate 110 b. Thetransistor TFT, the organic light-emitting diode OLED, and the colorfilter layer CF may be included in a light-emitting area SPA of asubpixel.

Similarly to the first example embodiment, the display panel accordingto the second example embodiment can simplify the process compared tothe test example because, when the common electrode layer 123 is formed,it may come into electrical contact with the second pixel electrodelayer portion 120 b at the uppermost part of the auxiliary line AUX.

The display panel according to the second example embodiment isdifferent from that of the first example embodiment in that it has theblack matrix layer BM and the color filter layer CF, and the third pixelelectrode 120 c is on the organic insulating layer 121. As anotherexample, a black base material may be included in one or more of: thefirst passivation layer 118, the second passivation layer 119, and theorganic insulating layer 121. When the display panel according to thesecond example embodiment has the color filter layer CF, the organicemissive layer 122 may be made of a material that may emit white light.Moreover, in the display panel according to the second exampleembodiment, the third pixel electrode layer 120 is not removed, but maybe left on the organic emissive layer 121, e.g., to simplify themanufacturing process. However, this is merely an example, and the thirdpixel electrode layer portion 120 c on the organic emissive layer 121may be removed, as described in the first example embodiment.

Third Example Embodiment

FIGS. 17 to 19 illustrate examples of an array of auxiliary linesaccording to a third example embodiment of the present disclosure.

As shown in the examples of FIGS. 17A and 17B, the auxiliary line AUXdescribed above in the foregoing first and second example embodimentsmay be arranged vertically in the display area AA of the display panel110, e.g., in the same direction as the data lines DL1 to DLn. Theauxiliary line AUX may be disposed between every column of subpixels SP,as shown in FIG. 17A, or may be placed between at least every secondcolumn of subpixels SP, as shown in FIG. 17B.

As shown in the examples of FIGS. 18A and 18B, the auxiliary line AUXdescribed above in the foregoing first and second example embodimentsmay be arranged horizontally in the display area AA of the display panel110, e.g., in the same direction as the scan lines GL1 to GLm. Theauxiliary line AUX may be disposed between every row of subpixels SP, asshown in FIG. 18A, or may be disposed between at least every second rowof subpixels SP as shown in FIG. 18B.

As shown in the examples of FIGS. 19A and 19B, the auxiliary line AUXdescribed above in the foregoing first and second example embodimentsmay be arranged vertically and horizontally in the display area AA ofthe display panel 110. The auxiliary line AUX may be disposed betweenevery column of subpixels SP and between every row of subpixels SP asshown in FIG. 19A, or may be disposed between at least every secondcolumn of subpixels SP and between at least every second row ofsubpixels SP as shown in FIG. 19B.

Therefore, the auxiliary line AUX may be in the display area AA of thedisplay panel 110, e.g., to help reduce the resistance of the commonelectrode layer 123, and may be arranged in the form of a line or in theform of a mesh. Furthermore, the auxiliary line AUX may be on the outerside of the display area AA of the display panel 110, as well as on theinner side of the display area AA. The auxiliary line on the outer sideof the display area AA may be configured to surround at least two,three, or four sides of the display area AA.

As viewed from above, when an auxiliary line is formed to reduce theresistance of the display panel, embodiments of the present disclosuremay simplify the manufacturing process so that the auxiliary line andthe common electrode layer may come into direct contact with each otherthrough a deposition process. Moreover, embodiments of the presentdisclosure may improve brightness uniformity on a large-area displaypanel because the resistance of the display panel may be reduced usingthe common electrode layer and the auxiliary line. Furthermore,embodiments of the present disclosure may allow for the self-alignmentof pixel electrode layers based on an undercut structure, and may reducethe number of masks used.

It will be apparent to those skilled in the art that variousmodifications and variations may be made in the present disclosurewithout departing from the technical idea or scope of the disclosure.Thus, it may be intended that embodiments of the present disclosurecover the modifications and variations of the disclosure provided theycome within the scope of the appended claims and their equivalents.

What is claimed is:
 1. A light-emitting display device, comprising: afirst substrate; an interlayer insulating layer on the first substrate;a subpixel on the substrate, the subpixel comprising: a light-emittingarea; and a non-light-emitting area; a contact area on the firstsubstrate; a metal layer on the interlayer insulating layer on the firstsubstrate, the metal layer comprising a plurality of metal layerportions, the plurality of metal layer portions comprising: first andsecond metal layer portions disposed separately in the light-emittingarea and in the non-light-emitting area; and a third metal layer portiondisposed in the contact area; a cover layer comprising a plurality ofcover layer portions comprising first to third cover layer portionsdisposed separately and respectively corresponding to the first to thirdmetal layer portions; a first passivation layer covering the third coverlayer portion in the contact area, the first passivation layer exposingpart of the third cover layer portion; a second passivation layercovering the first cover layer portion and the second cover layerportion, exposing part of the second cover layer portion, covering thefirst passivation layer, and exposing part of the third cover layerportion; a pixel electrode layer comprising a plurality of pixelelectrode layer portions comprising: a first pixel electrode layerportion on the second cover layer portion; and a second pixel electrodelayer portion on the third cover layer portion; an organic insulatinglayer on the second passivation layer, the organic insulating layercomprising: an opening exposing part of the first pixel electrode layer;and a contact hole exposing part of the second pixel electrode layer; anorganic emissive layer on the organic insulating layer and the first andsecond pixel electrode layers; and a common electrode layer on theorganic emissive layer, the common electrode layer being electricallyconnected to the second pixel electrode layer in the contact area,wherein the opening comprises a first undercut shape including a recessof the second passivation layer into the bottom of the organicinsulating layer partially exposing the bottom of the organic insulatinglayer, and wherein the contact hole comprises a second undercut shapeincluding a recess of the first passivation layer and the secondpassivation layer into the bottom of the organic insulating layerpartially exposing the bottom of the organic insulating layer.
 2. Thelight-emitting display device of claim 1, wherein the first passivationlayer and the second passivation layer have different thicknesses. 3.The light-emitting display device of claim 1, wherein the height of thesecond undercut shape is greater than the height of the first undercutshape.
 4. The light-emitting display device of claim 3, wherein, in aspace under the second undercut shape, the second pixel electrode layerdirectly contacts a sidewall of at least one of the first and secondpassivation layers.
 5. The light-emitting display device of claim 4,wherein the common electrode layer and the second pixel electrode layerelectrically contact each other on the sidewall of the secondpassivation layer exposed in the contact area.
 6. The light-emittingdisplay device of claim 4, wherein the common electrode layer is overall layers exposed in the contact area.
 7. The light-emitting displaydevice of claim 1, wherein a first portion of the organic emissive layeron the organic insulating layer and a second portion of the organicemissive layer on the first pixel electrode layer are separated fromeach other by the first undercut shape.
 8. The light-emitting displaydevice of claim 1, further comprising a black base material in one ormore of: the first passivation layer, the second passivation layer, andthe organic insulating layer.
 9. The light-emitting display device ofclaim 1, wherein: the first pixel electrode layer portion and the commonelectrode are separated from each other by the first undercut shape; andthe second pixel electrode layer portion directly contacts the commonelectrode.
 10. The light-emitting display device of claim 1, furthercomprising a third pixel electrode portion on the organic insulatinglayer.
 11. A light-emitting display device, comprising: a firstsubstrate; a subpixel on the substrate; a contact area on the firstsubstrate; a cover layer comprising a plurality of cover layer portionscomprising first to third cover layer portions, each of the first tothird cover layer portions being separated from each other; a firstpassivation layer covering the third cover layer portion in the contactarea, the first passivation layer exposing part of the third cover layerportion; a second passivation layer covering the first cover layerportion and the second cover layer portion, exposing part of the secondcover layer portion, covering the first passivation layer, and exposingpart of the third cover layer portion; a pixel electrode layercomprising a plurality of pixel electrode layer portions comprising: afirst pixel electrode layer portion on the second cover layer portion;and a second pixel electrode layer portion on the third cover layerportion; an organic insulating layer on the second passivation layer,the organic insulating layer comprising: an opening exposing part of thefirst pixel electrode layer; and a contact hole exposing part of thesecond pixel electrode layer; an organic emissive layer on the organicinsulating layer and the first and second pixel electrode layers; and acommon electrode layer on the organic emissive layer, the commonelectrode layer being electrically connected to the second pixelelectrode layer in the contact area, wherein the opening comprises afirst undercut shape including a recess of the second passivation layerinto the bottom of the organic insulating layer partially exposing thebottom of the organic insulating layer, wherein the contact holecomprises a second undercut shape including a recess of the firstpassivation layer and the second passivation layer into the bottom ofthe organic insulating layer partially exposing the bottom of theorganic insulating layer, and wherein a distance between the third coverlayer portion and the organic insulating layer is different from adistance between the first cover layer portion and the organicinsulating layer.
 12. The light-emitting display device of claim 11,wherein, in a space under the second undercut shape, the second pixelelectrode layer directly contacts a sidewall of at least one of thefirst and second passivation layers.
 13. The light-emitting displaydevice of claim 12, wherein the common electrode layer and the secondpixel electrode layer electrically contact each other on the sidewall ofthe second passivation layer exposed in the contact area.
 14. Thelight-emitting display device of claim 12, wherein the common electrodelayer is over all layers exposed in the contact area.
 15. Thelight-emitting display device of claim 11, further comprising a blackbase material in one or more of: the first passivation layer, the secondpassivation layer, and the organic insulating layer.
 16. A method ofmanufacturing a light-emitting display device, the method comprising:providing a first substrate; providing a subpixel on the substrate, theproviding the subpixel comprising: providing a light-emitting area; andproviding a non-light-emitting area; providing a contact area on thefirst substrate; providing a cover layer comprising providing aplurality of cover layer portions comprising first to third cover layerportions disposed separate from each other; covering the third coverlayer portion in the contact area with a first passivation layer, thefirst passivation layer exposing part of the third cover layer portion;providing a second passivation layer covering the first cover layerportion and the second cover layer portion, exposing part of the secondcover layer portion, covering the first passivation layer, and exposingpart of the third cover layer portion; providing a pixel electrode layercomprising providing a plurality of pixel electrode layer portionscomprising: providing a first pixel electrode layer portion on thesecond cover layer portion; and providing a second pixel electrode layerportion on the third cover layer portion; providing an organicinsulating layer on the second passivation layer, the providing theorganic insulating layer comprising: providing an opening that exposespart of the first pixel electrode layer; and providing a contact holethat exposes part of the second pixel electrode layer; providing anorganic emissive layer on the organic insulating layer and the first andsecond pixel electrode layers; and providing a common electrode layer onthe organic emissive layer, the common electrode layer beingelectrically connected to the second pixel electrode layer, wherein theopening is provided with a first undercut shape formed by recessing thesecond passivation layer into the bottom of the organic insulating layerto partially expose the bottom of the organic insulating layer, whereinthe contact hole is provided with a second undercut shape formed byrecessing the first passivation layer and the second passivation layerinto the bottom of the organic insulating layer to partially expose thebottom of the organic insulating layer, and wherein the first and secondpixel electrode portions are self-aligned.
 17. The method of claim 16,wherein a first portion of the organic emissive layer on the organicinsulating layer and a second portion of the organic emissive layer onthe first pixel electrode layer are separated from each other by thefirst undercut shape.
 18. The method of claim 16, further comprisingproviding a third pixel electrode layer portion on the organicinsulating layer simultaneously to the providing the first and secondpixel electrode layer portions, the third pixel electrode layer portionbeing self-aligned.
 19. The method of claim 18, further comprisingremoving the third pixel electrode layer portion.
 20. The method ofclaim 16, wherein: the first pixel electrode layer portion and thecommon electrode are separated from each other by the first undercutshape; and the second pixel electrode layer portion directly contactsthe common electrode.